Hyperacusis and Helicopters I've been interested in photographing helicopters lately. Partly
because helicopters are just kinda nifty, and partly because there
are a bunch of 'em that frequently fly nearby. So I've been keeping
an ear toward hearing them approach so I can go grab a long lens and
lean out the window.
When I'm experiencing fibromyalgia-related hyperacusis (auditory
hyperacuity), I can hear them from too far away to be useful. Worse,
I keep hearing sounds that resemble those made by helicopters, but
aren't. I think that's from a certain pattern of truck traffic on
I95. (Some nearer street vehicles also mimic helicopter sounds, but
I can distinguish them more quickly because the direction the sound
comes from changes in the wrong way. The sound that I think is
coming from I95 has enough reflections -- the effect that makes
'ghosts' in analog television -- that it's hard to hear an exact
direction in it. Reflections are a challenge regardless, but this
seems to have extra bounces.)
I'm still trying to learn to distinguish street-legal motorcycles,
scooters, and illegal dirt bikes by sound at a distance. The scooters
and the dirt bikes sound awfully similar.